Changes in leaves of susceptible and resistant Solanum dulcamara infested by the gall mite Eriophyes cladophthirus (Acarina, Eriophyoidea)

1981 ◽  
Vol 59 (5) ◽  
pp. 875-882 ◽  
Author(s):  
E. Westphal ◽  
R. Bronner ◽  
M. Le Ret
Keyword(s):  
Hypersensitive Response ◽  
Cell Walls ◽  
Polyphenolic Compounds ◽  
Epidermal Cells ◽  
Solanum Dulcamara ◽  
Injured Cell ◽  
Feeding Sites ◽  
Gall Mite ◽  
Necrotic Region

Eriophyes cladophthirus perforates the wall of epidermis cells during feeding on young susceptible leaves and provokes the formation of cone-shaped feeding punctures. Callose is detected near the puncture after 20 min and the injured cells are transformed into nutritive cells. Nutritive cells are induced near the feeding sites on susceptible plants, whereas only necrotic cells appear near feeding sites on resistant plants.Mites feeding on resistant plants rapidly initiate a hypersensitive response detectable after 10 min on injured epidermal cells which then leads to severe necrosis of surrounding tissues after 1 h. No typical feeding punctures or callose deposits appear on injured cell walls. Polyphenolic compounds are detected in the necrotic region after 4 h.

Cytological studies of the hypersensitive death of cowpea epidermal cells induced by basidiospore-derived infection by the cowpea rust fungus

1991 ◽  
Vol 69 (6) ◽  
pp. 1199-1206 ◽  
Author(s):  
C. Y. Chen ◽  
Michele C. Heath
Keyword(s):  
Hypersensitive Response ◽  
Cell Walls ◽  
Cytoplasmic Streaming ◽  
Rust Fungus ◽  
Fungal Growth ◽  
Inhibitory Effect ◽  
Epidermal Cells ◽  
Plant Cell Walls ◽  
Powdery Mildew Fungus ◽  
Uromyces Vignae

The cytological responses to the monokaryotic primary hyphae of the cowpea rust fungus (Uromyces vignae Barcl.) were observed in vein epidermal cells of a resistant and a susceptible cowpea cultivar. Unlike the previously examined response to haustoria of a nonpathogenic powdery mildew fungus, plant cell walls did not become autofluorescent in response to fungal penetration, and the primary hypha only rarely became encased. Following fungal penetration, the response of invaded cells of the resistant, intact plant could be divided into the following stages: (I) cytoplasmic streaming normal; (II) cytoplasmic streaming slow or stopped, Brownian motion of particles visible in the vacuole, granulated cytoplasm aggregated along the cell walls, some host nuclei disappeared; and (III) protoplast collapsed. Epidermal tissue of the resistant cultivar did not exhibit stages II–III when detached and mounted in water 12 h after inoculation and examined 9 h later. The frequency of stage III increased when the tissue was mounted in CaCl2, Ca(NO3)2, and KNO3, but only in a kinetin solution did it approximate that in attached tissue. Although kinetin inhibited fungal growth in both the resistant and the susceptible cultivar, the hypersensitive response occurred only in the former, suggesting that kinetin affects the hypersensitive response directly rather than through its inhibitory effect on the fungus. Key words: cowpea, Vigna unguiculata, cowpea rust fungus, Uromyces vignae (Barcl.), hypersensitivity.

The epidermis in Passerina/ (Thymelaeaceae): structure, function and taxonomic significance

Bothalia ◽  
2000 ◽  
Vol 30 (1) ◽  
pp. 69-86 ◽  
Author(s):  
C. L. Bredenkamp ◽  
A. E. Van Wyk
Keyword(s):  
Cell Walls ◽  
Mediterranean Climate ◽  
High Light Intensity ◽  
Epidermal Cells ◽  
Cell Orientation ◽  
Abaxial Surface ◽  
Epidermal Structure ◽  
Interspecific Differences ◽  
Epidermal Features ◽  
Structural Adaptations

Epidermal features were studied in all 17 species of Passerina, a genus endemic to southern Africa. Leaves in Passerina are inversely ericoid, the adaxial surface concave and the abaxial surface convex. Leaves are inversely dorsiventral and epistomatic. The adaxial epidermis is villous, with unicellular, uniseriate trichomes and relatively small thin-walled cells, promoting flexibility of leaf margins owing to turgor changes. In common with many other Thymelaeaceae, abaxial epidermal cells are large and tanniniferous with mucilaginous cell walls. The cuticle is adaxially thin, but abaxially well devel­oped, probably enabling the leaf to restrict water loss and to tolerate high light intensity and UV-B radiation. Epicuticular waxes, present in all species, comprise both soft and plate waxes. Epidermal structure proves to be taxonomically impor­tant at family, genus and species levels. Interspecific differences include arrangement of stomata and presence or absence of abaxial epidermal hair. Other diagnostic characters of the abaxial epidermal cells are arrangement,size and shape, cutic- ular ornamentation and presence or absence of wax platelets. Two groups of species on the basis of abaxial epidermal cell orientation are recognised. Many leaf epidermal features in Passerina are interpreted as structural adaptations to the Mediterranean climate of the Cape.

A new species and comparative morphology of Vesselowskya (Cunoniaceae)

2001 ◽  
Vol 14 (2) ◽  
pp. 175 ◽  
Author(s):  
Andrew C. Rozefelds ◽  
Richard W. Barnes ◽  
Belinda Pellow
Keyword(s):  
New Species ◽  
Cell Walls ◽  
New South ◽  
Comparative Morphology ◽  
Epidermal Cells ◽  
The Other ◽  
Abaxial Surface ◽  
South Wales ◽  
Central Column ◽  
A New Species

The vegetative and reproductive morphology of Vesselowskya Pampanini, southern marara, is described and illustrated in detail. The variation within V. rubifolia (F.Muell.) Pampanini sens. lat. is shown to be greater than has previously been recognised, with the differences identified supporting the recognition of a new segregate species, V. venusta Rozefelds, R.W.Barnes and Pellow sp. nov. Vesselowskya venusta occurs in the Barrington Tops Plateau of New South Wales and differs from V. rubifolia in possessing hairs on the abaxial surface of the sepals and lacking both a prominent distal connective protrusion on the anthers and colleters at the base of the stipules. The two Vesselowskya species are dioecious with a vestigial ovary in staminate flowers and reduced stamens in pistillate flowers. Dioecy is more pronounced in Vesselowskya, than in some Weinmannia species, and in both genera is expressed through reduction in the size of the ovaries in staminate flowers, and stamens in pistillate flowers. Vesselowskya shares with the other genera in the tribe Cunonieae (Pancheria, Weinmannia and Cunonia), a central column in the fruits, and Cunonia-type stipules, but differs from these genera in having valvate aestivation, digitate leaves, craspedodromous secondary venation with secondary veins terminating at a tooth, tuft domatia along the midrib, adaxial epidermal cells with strongly sinuous cell walls and the absence of hydathodes.

Histopathological and ultrastructural comparison of Stemphylium sarcinaeforme and S. botryosum on red clover foliage

1978 ◽  
Vol 56 (17) ◽  
pp. 2097-2108 ◽  
Author(s):  
Verna J. Higgins ◽  
G. L. Lazarovits
Keyword(s):  
Cell Walls ◽  
Light And Electron Microscopy ◽  
Red Clover ◽  
Epidermal Cells ◽  
Blue Staining ◽  
Mesophyll Cells ◽  
Toluidine Blue Staining ◽  
Different Types ◽  
Wall Appositions ◽  
Palisade Cells

As part of a continuing study of non-host resistance, red clover leaves inoculated with the clover pathogen Stemphylium sarcinaeforme, or the closely related alfalfa pathogen S. botryosum, were examined by light and electron microscopy to compare the events occurring in the initial stages of infection. Stemphylium botryosum penetrated leaves primarily via the stomata with resultant death of the guard cells and with varying effects on adjacent epidermal cells. Appressoria were frequently formed, and although they rarely resulted in successful penetrations, the contacted epidermal cells were often markedly affected as judged by toluidine blue staining. Growth of hyphae was intercellular but very limited in its extent. At some infection sites, one to several mesophyll cells underwent extensive plasmolysis and cytoplasmic disruption. Less severely affected mesophyll cells contained large lipid bodies, abundant rough endoplasmic reticulum, and Golgi vesicles and had wall appositions at points of contact with necrotic cells or with hyphae. Stemphylium sarcinaeforme generally penetrated between or directly through the epidermal cells, causing death of the contacted cells. Hyphae grew intercellularly or intracellularly in the palisade tissue and hyphal elongation was considerably more rapid than that of S. botryosum. Palisade cells adjacent to, or containing, the hyphae underwent several different types of cytoplasmic deterioration. Mesophyll cells surrounding these areas showed the same features as comparable cells in tissue infected by S. botryosum. In tissue infected by either fungus, the exterior of host cell walls was coated with a layer of extracellular material.

Histopathology of infection of bean with Pythium myriotylum compared with infection with other Pythium species

1975 ◽  
Vol 53 (17) ◽  
pp. 1786-1795 ◽  
Author(s):  
Roberta L. Dow ◽  
Robert D. Lumsden
Keyword(s):  
Cell Walls ◽  
Vascular Tissue ◽  
Tap Water ◽  
Pythium Ultimum ◽  
Epidermal Cells ◽  
Pythium Species ◽  
Pythium Myriotylum ◽  
Zoospore Production ◽  
Aerial Hyphae ◽  
Small Clusters

Clusters of abundant appressoria formed from branching hyphae of mycelial inoculum of Pythium myriotylum on the surface of bean hypocotyls and roots. Pythium aphanidermatum usually produced single appressoria, but sometimes small clusters of appressoria. Pythium ultimum produced only single appressoria. Early pathogenesis of all species was characterized by rapid radial growth of hyphae in the epidermal cells, which was more rapid than in the cortex. These hyphae were constricted at the host cell walls. Invaded tissue and adjacent cells stained differently from healthy cells with all isolates. Aerial hyphae were produced from vesicles below the cuticle or within epidermal cells soon after infection was established. Safranin-staining materials were observed in the xylem, phloem, and tannin sacs. Zoospores of P. myriotylum and P. aphanidermatum germinated and produced long prepenetration hyphae, which branched and formed single appressoria. Oospores of P. myriotylum, P. aphanidermatum, and P. ultimum, after germination, produced branched hyphae and single appressoria. Penetration, rapid advance through epidermal cells, and ramification of cortical and vascular tissue were identical with those of mycelial inoculum. Sporangia of all three species formed intercellularly and intracellulary within 48 h and predominantly in the epidermis and upper cortex. Oogonia were produced intercellularly and intracellularly in 4 day s throughout the tissue, but mainly in the inner two thirds of the cortex. Sporangia of P. myriotylum and P. aphanidermatum in infected bean hypocotyls germinated within 3 h when flooded with tap water and produced zoospores within 6 h. When similar tissue was air-dried for 3 days or rapidly dried for 3 h. there was neither germination nor zoospore production.

scholarly journals Micromorphology of endemic Centaurea glaberrima subsp. divergens (Asteraceae)

2022 ◽  
Vol 81 (1) ◽  
Author(s):  
Milan Gavrilović ◽  
Pedja Janaćković
Keyword(s):  
Cell Walls ◽  
Glandular Trichomes ◽  
Pollen Grains ◽  
Involucral Bract ◽  
Epidermal Cells ◽  
Leaf Epidermis ◽  
Abaxial Surface ◽  
Reproductive Structures ◽  
Anomocytic Stomata ◽  
First Time

In this study, the micromorphology of the vegetative and reproductive structures of the endemic Centaurea glaberrima Tausch subsp. divergens (Vis.) Hayek (Asteraceae), using scanning electron microscope (SEM), is presented for the first time. Uniseriate whip-like non-glandular and biseriate glandular trichomes are found on the surface of all aboveground parts (stem, leaves, peduncles, involucral bract). On the adaxial leaf epidermis ribbed thickenings (striation pattern) of outer periclinal cell walls, slightly curved anticlinal cell walls and anomocytic stomata are noticed. Rugose abaxial surface with thorny protuberances of the involucral bract is documented. Corolla is glabrous with longitudinally parallel epidermal cells with distinct straight outline. Isopolar, radially symmetric and tricolporate microechinate pollen grains are seen. Short stylar hairs, without cuticular striations, are present along the outer sides of the style, while the inner sides (abaxial surface) constitute the papillate stigmatic surface. Microcharacters found in cypsela are as follows: slightly ribbed body; rotund base; lateral and concave insertion; short, unicellular curly acute trichomes; smooth epidermis; fine-sulcate ornamentation; rod shaped epidermal cells with short, obtuse end walls and straight anticlinal walls; poorly developed minutely dentate pericarp rim; and dimorphic pappus with bristles of different length and morphology, with pinnules restricted to the margins of the bristles. The results obtained contribute to knowledge about the micromorphology of the studied endemic species and provide features for its better identification. The taxonomic significance of the analyzed characters is discussed. Some well defined microcharacters of the studied species might have taxonomic value

scholarly journals ANATOMY OF CHLOROTHALONIL-INDUCED GRAPE BERRY RUSSET

HortScience ◽  
1991 ◽  
Vol 26 (6) ◽  
pp. 762B-762
Author(s):  
Martin C. Goffinet ◽  
Roger C. Pearson
Keyword(s):  
Cell Wall ◽  
Cell Walls ◽  
Grape Berry ◽  
Epidermal Cells ◽  
Daughter Cells ◽  
Vitis Labruscana ◽  
Original Cell

Clusters of Vitis labruscana cv. Concord were grown either in full sun or canopy shade, and either not sprayed or sprayed with 3.4 Kg/Ha chlorothalonil every 2 wk from pre-bloom to veraison. Only sun-exposed, sprayed fruit produced skin russeting. Clusters of the very susceptible V. vinifera cv. Rosette were grown in direct sun, sprayed with chlorothalonil 4 times from bloom to veraison, in the presence or absence of purported anti-russeting agents. Heavy russet occurred in all treatments. Russet initiation was similar in the 2 cvs.: epidermal cells first died beneath spray residue in full sun, a phellogen then arose in the hypodermis, followed by periderm. Epidermal death began in `Rosette' within a wk of the bloom spray, but in `Concord' only after 2-3 wk post bloom and 3 sprays. `Concord' russet generally appeared as patches or scabs, whereas `Rosette' russet ranged from freckles, welts, scabs to large smooth burnished areas. In both cvs., unbroken russet consisted of uniform layers of phellum. New, deeper periderm initials arose beneath checks and cracks which formed as fruit enlarged. In `Concord', but not `Rosette', the daughter cells of each such initial were often enclosed in the original cell wall. In all cases of russet, cell walls in the periderm were suberized and sometimes lignified. Cells also contained much phenolic material.

scholarly journals Micromorphological study (ultrastructure of lamina surface, seeds, ultrasculpture of pollen grains) of Gladiolus L. species (Iridaceae Juss.) of Ukrainian flora

2014 ◽  
Vol 2 (4) ◽  
pp. 21-27 ◽  
Author(s):  
Svitlana L. Zhygalova ◽  
Oksana A. Futorna ◽  
Anatoliy Levanets
Keyword(s):  
Surface Structure ◽  
Seed Coat ◽  
Cell Walls ◽  
Morphological Characteristics ◽  
Pollen Grains ◽  
Epidermal Cells ◽  
Diagnostic Feature ◽  
Diagnostic Features ◽  
Surface Ultrastructure ◽  
Genus Level

Abstract Micro-morphological characteristics of the four Gladiolus L. species of the Ukrainian flora (G. imbricatus L., G. italicus Mill., G. palustris Gaudin and G. tenuis M. Bieb.) as regards leaves, seeds and pollens are presented with this investigation in a detailed way. An examination of the surface structure of the leaves, seeds and pollen grains of the Gladiolus species indicates that the characteristics of the ultrastructure of leaves and of pollen grains are not diagnostic for distinguishing species, but they could be important at genus level (leaves: features such as being amphistomatic, having the same quantity of immersed stomata on both surfaces and having a high stomata index, the presence and localisation of papillae, the shape of epidermal cells; pollen grains: monosulcate type with two operculums). However, the type of surface ultrastructure of the seed coat is a diagnostic feature as at genus level so for species. It can be mentioned that propose the use of features such as the shape and position of the cicatricle, the type of cuticle, the shape and boundaries of cells of testa, and the anticlinal cell walls as diagnostic features at genera level. The shape of seeds, the presence and disposition of wing, the level of the periclinal cell walls of the seed coat and types of relief are additional diagnostic features for distinguishing of Gladiolus species.

Localization of cadmium in granules within differentiating and mature root cells

1987 ◽  
Vol 65 (4) ◽  
pp. 643-646 ◽  
Author(s):  
W. E. Rauser ◽  
C. A. Ackerley
Keyword(s):  
Zea Mays ◽  
Cell Walls ◽  
Zea Mays L ◽  
Epidermal Cells ◽  
Root Cells ◽  
Dense Granules ◽  
Parenchyma Cells ◽  
Undifferentiated Cells ◽  
Mature Root

Cadmium was found in electron-dense granules inside root parenchyma cells of Agrostis gigantea Roth and of Zea mays L. (maize) exposed to 3 mmol m−3 CdSO4. Cadmium-bearing granules were found in the cytoplasm and vacuoles of differentiating and mature cells and in nuclei of undifferentiated cells. Cadmium-bearing granules were absent from cell walls and epidermal cells. In addition to Cd, the electron-dense granules contained variable proportions of Ca, Fe, Ni, P, Pb, and Zn.

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